Function CheckBlob

src/blobcache/blobcache.go:419–436

CheckBlob checks that the data matches the expected CID. If there is a problem, it returns an ErrBadData.

(ha HashAlgo, salt, cid *CID, data []byte)

// CheckBlob checks that the data matches the expected CID.
// If there is a problem, it returns an ErrBadData.
func CheckBlob(ha HashAlgo, salt, cid *CID, data []byte) error {
	var actualCID CID
	if salt == nil {
		actualCID = ha.Hash(data)
	} else {
		hf := ha.KeyedHash
		actualCID = hf(salt, data)
	}
	if *cid != actualCID {
		return ErrBadData{
			Salt:     salt,
			Expected: *cid,
			Actual:   actualCID,
			Len:      len(data),
		}
	}
	return nil
}